Drive mechanism

ABSTRACT

A drive mechanism for using a high-pressure fluid to directly impart rotation to a rotatably mounted body, the mechanism including cylinders mounted concentrically around the axis of rotation of the body and each containing a piston reciprocably mounted in each cylinder for reciprocating movement in a direction which is radial relative to the rotational axis of the body. A piston rod or equivalent structure extends radially outwardly from the piston and bears against a continuous surface which eccentrically surrounds the rotational axis of the body. Fluid passageways extend through the body and communicate with each cylinder. A stationary structure is provided adjacent the openings of the fluid passageways into the body, and is ported to alternately admit fluid at relatively high pressure, and then fluid at relatively lower pressure to each of the fluid passageways in the body as the body is rotated about its axis. The sequence and timing of those pressure variations in each fluid passageway, and thus in each radial cylinder communicating therewith, is such that relatively high-pressure fluid acts against each piston when its piston rod, in contacting the continuous eccentric surface, develops a reaction force which causes the body to rotate in one direction, and relatively lowpressure fluid acts against each piston when its piston rod, in contacting the continuous eccentric surface, develops a reaction force which opposes rotation of the body in said one direction.

United States Patent Hashemi 1 Feb. '15, 1972 [54] DRIVE MECHANISM 57 ABSTRACT [72] Inventor: Hedi T. Hashemi, Norman, Okla. A drive mechanism for using a high-pressure fluid to directly impart rotation to a rotatably mounted body, the mechanism [73] Assgnee' corporation Dallas including cylinders mounted concentrically around the axis of 22 Filed; 5 1970 rotation of the body and each containing a piston reciprocably mounted in each cylinder for reciprocating movement in a PP 9,268 direction which is radial relative to the rotational axis of the body. A piston rod or equivalent structure extends radially outwardly from the piston and bears against a continuous sur- [52] U.S.Cl ..91/483, 91/492,417/225 face which eccenmcany surrounds the rotational axis of the [51] Int. Cl ..F0lb 13/06 body Fluid passageways extend through the body and [58] Field of Search ..4l7/225;91/492, 485 municate with each cylinden A stationary structure is vided adjacent the openings of the fluid passageways into the [56] References cued body, and is ported to alternately admit fluid at relatively high pressure, and then fluid at relatively lower pressure to each of UNITED STATES PATENTS the fluid passageways in the body as the body is rotated about 3,391,538 7/1968 Orlofi et al. ..91/492 its axis. The sequence and timing of those pressure variations 2,728,302 12/1955 Ferris ..91/492 in e h fl p g y, and thus in each radial cylinder 3,508,466 4/1970 Tyler ,91/472 communicating therewith, is such that relatively high-pressure 3 090,3 1 5 1 9 3 orshansky 91 472 fluid acts against each piston when its piston rod, in contacting 3,426,695 2/1969 Klaus ...9l/493 the continuous eccentric surface, develops a reaction force 3 1 5 0 3 19 5 Bumham "91/483 which causes the body to rotate in one direction, and relative- 2 454 41 1/ 94g Zimmeman 417/225 ly low-pressure fluid acts against each piston when its piston 2,934,043 4/1960 Del Rico ..91/492 mat comacting eccentric Surface, devebps a reaction force which opposes rotation of the body in said FOREIGN PATENTS OR APPLICATIONS one direction.

1,027,987 11/1956 Germany ..91/492 5 Claims, 7 Drawing Figures Primary ExaminerWilliam L. Freeh Anomey-Dunlap, Laney, Hessin & Dougherty lll1l1lll1l1l1lll1l1ll=1i1 59 unnnuunmiuuuuu /2 5a a a; 90 t I l .21iseszzfiofinrmnnmnflflflill E 6 n i: It. I! A; A 44 mews lfrlk 9.20.23 2

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PATENYEQFEB 15 I972 SHEET 1 or 3 M/l/EA/MP HAD/ I HAS'HEM/ /2/22 ATTOP/VEX? PATENTED FEB 1 5 m2 SHEET 3 BF 3 IQI DRIVE MECHANISM BACKGROUND OF THE INVENTION l. Field of the Invention This invention relates to drive mechanisms in which fluid pressure is used to drive rotatably mounted bodies in rotation, and more particularly, but without being limited thereto, to a hydraulic drive system in which a pressurized liquid passing through an energy exchange engine is utilized to supply the power for driving the exchange engine.

2. Brief Description of the Prior Art In U.S. Pat. No. 3,431,747, there is illustrated and described an engine for exchanging energy between highand low-pressure systems. This engine includes a cylindrical rotor having axial bores therethrough which, as the rotor is rotated, are periodically communicated with the ports formed in seal plates disposed at opposite ends of the rotor. A freely displaceable movable piston element is located in each rotor bore, and through the ported seal plates, high-pressure and low-pressure fluids are alternately introduced to the bores as the rotor is rotated so that the pressure energy of the highpressure fluid is efficiently transferred to the low-pressure fluid. The utilization of this device in the production of fresh water from saline aqueous solutions by exchange crystallization is described.

Since the energy requirement to recover fresh water from saline aqueous solutions is of paramount importance to the economic feasibility of any such process, the power required to drive the rotor of the described energy exchange engine is a critical consideration. As it is proposed to power the rotor forming a portion of the energy exchange engine described in U.S. Pat. No. 3,431,747, a motor is drivingly connected to a shaft which projects from the rotor, and in actual practice, the rotor of this type of exchange engine has heretofore been typically driven by a 2-horsepower electric motor in order to produce uniform and stable rotation of the engine under varying tests and pilot plant conditions. Less than one-quarter horsepower is actually needed, however, to offset the friction loss generated by the seals and bearings which hold the rotor in place and which permit the high and low-pressure fluids to be charged to the axial bores in the rotor. The rest of the consumed power is lost in the necessary gear reduction mechanism by which power is transferred from the motor to the rotor shaft.

In energy exchange engines of the type described, several disadvantages characterize the use of an electric motor as the prime mover for the rotor. When this type of power source is employed, the energy exchange engine is not self-sufficientthat is, it is dependent upon an external source of power in order to operate in the manner required, There is, moreover, as indicated, a considerable power loss which results from the necessary employment of a gear reduction mechanism. Also, since the load generated by the energy exchange engine is variable during its operation, an electric motor utilized for driving the rotor must necessarily have a substantially higher power rating than that which is required for normal operation of the engine during the average load requirement. Finally, the electric motor and gear reduction mechanism constitute a substantial part of the capital and operating cost of the engine.

BRIEF DESCRIPTION OF THE PRESENT INVENTION The present invention constitutes a drive mechanism employing a pressurized fluid as the ultimate energy source, and which can be utilized for driving rotatably mounted bodies in rotation. The drive mechanism is peculiarly well adapted for use in conjunction with an energy exchange engine of the type described. In this application, the pressurized fluids utilized for powering the drive mechanism are the liquids or slurries between which pressure is transferred in the engine.

Broadly described, and without respect to any specific application, the drive mechanism of the present invention comprises a body mounted for rotation about an axis extending therethrough and having fluid passageways extending into the body from an exposed surface thereof, with the openings to said fluid passageways spaced radially outwardly from the axis of rotation of the body. At least one, and preferably a plurality of cylinders are connected to the body for rotation therewith, and are disposed radially outwardly relative to the axis of rotation of the body. Such cylinders may be merely cavities or bores formed in the body, or may be formed separately and secured in any suitable manner to the body for rotation concurrently therewith.

Each cylinder contains piston means which is reciprocably mounted in the cylinder for movement radially with respect to the axis of rotation of the body, and the passageways in the body each communicate with one of the cylinders radially inwardly of the piston means which is located therein. At least one continuous surface is provided radially outwardly from the axis of rotation of the body and on the opposite side of the cylinders from this axis, and over at least a portion of its total extent, each of said continuous surfaces is eccentrically shaped relative to the axis of rotation of the body. The piston means in the several cylinders each contact one of the continuous surfaces, and move across the eccentric portion thereof during rotation of the body. A ported structure is disposed adjacent the body and has a plurality of ports formed therethrough in a position to register in sequence with the fluid passageways in the body during rotation of the body, and thus to alternately deliver relatively high-pressure fluid to each passageway, and then lower-pressure fluid thereto. The arrangement of these ports in relation to the cylinders and the continuous surfaces is such that the relatively high-pressure fluid acts against each piston means at a time when it contacts an eccentric portion of one of said continuous surfaces at a location such that a reaction force is developed which drives the body in rotation in one direction, and the relatively low-pressure fluid acts against the piston means either at a time when no torque is developed by reaction forces, or when a reaction force is developed which opposes rotation of the body in said one direction.

In a preferred embodiment of the invention, the rotatably mounted body is the cylindrical rotor of an energy exchange engine, and the ported structure utilized includes a pair of seal plates located at each end of the rotor, and having highand low-pressure ports therethrough which alternately register with axial bores extending over the length of the rotor and substantially parallel to its rotational axis. The cylinders which carry the described piston means are preferably formed in hydraulic drive units which are interposed between each of the seal plates and the respective adjacent ends of the cylindrical rotor. In this position, the inner end of each of the piston means is exposed to the pressure of fluid in the axially extending bores of the rotor, and the other end projects radially outwardly into contact with the continuous surface carrying the described eccentricity. The rotor is caused to turn as a result of the torque generated by the pressure exerted on the eccentric portion of the continuous surfaces by the piston means at a time when those bores of the rotor which communicate with the cylinders carrying these piston means are in communica' tion with one or more high-pressure ports through the seal plate.

From the foregoing broad description of the invention, it will be perceived that an important object of the invention is to provide a drive mechanism by which fluid pressure can be utilized for the generation of torque in order to drive a rotatable body in rotation.

An additional object of the invention is to provide a relatively mechanically simple, inexpensively constructed drive mechanism, using a pressurized fluid as an energy source, and having relatively few moving parts.

A further and more specific object of the invention is to provide an energy exchange engine for transferring pressure energy from a relatively high-pressure fluid to a relatively lowpressure fluid, which energy exchange engine is self-sufficient in providing its own powerfor the purpose of rotating a rotor forming a portion thereof.

Another object of the invention is to provide an energy exchange engine which has no exposed moving parts and which requires no gear reduction device in order to operate the engine.

An additional object of the invention is to provide an energy exchange engine which includes a rotatably mounted rotor which can be driven by the application of an easily and selectively variable torque, at a selectively varied speed and in a manner which permits a selected power output to be obtained.

Yet another object of the invention is to provide an energy exchange engine of high efficiency in which the work of expansion of the high-pressure liquid in the bores of a rotor forming a portion of the engine is sufficient to generate the required torque so that the power used to drive the rotor of the engine in rotation can come from recovering at least a portion of the losses which otherwise would occur due to sudden depressurization of the high-pressure liquid which is charged to the engine.

In addition to the foregoing described objects and advantages, additional objects and advantages of the invention will become apparent as the following detailed description of preferred embodiments of the invention is read in conjunction with the accompanying drawings which illustrate the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a view, partially in section and partially in elevation, of an engine for exchanging energy between highand low-pressure systems, which engine incorporates the drive mechanism of the present invention.

FIG. 2 is a sectional view taken along line 2-2 of FIG. 1.

FIG. 3 is a diagrammatic illustration of the manner in which torque is developed by the drive mechanism of the present invention, showing the relation of the drive mechanism to certain parts of an energy exchange engine of the type depicted in FIG. 1,with which the drive mechanism may be used.

FIG. 3A is a vector diagram illustrating the direction of applied and reaction forces developed in drive mechanism illustrated in FIG. 3.

FIG. 4 is a diagram illustrating the manner in which certain parts of the drive mechanism of the invention can be varied in their relation to each other in order to selectively control the torque developed by the drive mechanism.

FIG. 5 is a view similar to the sectional view of FIG. 2, by illustrating a portion of a modified embodiment of the invention.

FIG. 6 is a diagrammatic illustration of the manner in which yet another embodiment of the invention is constructed.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION In order to more clearly explain the operation principles of the drive mechanism of the present invention, as well as to facilitate description of a preferred application of this drive mechanism in combination with certain additional structure constituting an energy exchange engine for exchanging energy between highand low-pressure systems, reference will initially be made to FIG. 1 which shows an energy exchange engine of this type having the drive mechanism of the present invention incorporated therein. The engine includes a solid cylindrical rotor 10 which has a pair of spaced end faces 12 and 14. Extending through the rotor 10 in an axial direction are a plurality of circumferentially spaced, substantially parallel fluid passageways or bores of generally circular cross section. Two of these axially extending bores are perceptible in FIG. 1, and are designated by reference numerals l6 and 18. It will be noted that the bores 16 and 18 each open at their opposite ends in the end faces 12 and 14 of the rotor 10, and this is characteristic of all of the axially extending bores, of which there are a total number of eight spaced circumferentially from each other around the rotor.

Pressed into the two end portions of each of the bores are ball stops. The ball stops at the opposite ends of the elongated, axially extending bore 16 are designated by reference numerals 20 and 22, and those at the opposite ends of the elongated axially extending bore 18 are designated by reference numerals 24 and 26. A small spherical member or ball 28 is rollably mounted in each axial bore and effectively forms a free piston reciprocably located in the bore and dividing the bore into two chambers.

Surrounding the cylindrical rotor 10 is a housing 32. The housing 32 has an internal cylindrical wall 320 which is positioned in contact with the cylindrical outer peripheral wall of an eccentric sleeve 34. The eccentricity of the sleeve 34 refers to the configuration and location of its inner peripheral surface 34a with respect to the rotational axis of the rotor 10 which extends through the rotor and coaxially along a pair of stub shafts 33 and 35 extending from the opposite end faces 12 and 14 of the rotor. It will be noted in referring to FIG. 1 that the housing 32 is of greater axial length than the rotor 10 so that it projects beyond the end faces 12 and 14 of the rotor.

A pair of end or closure plates 39 and 36 are secured to the housing 32 by axially extending bolts 37. The closure plate 39 is provided with a centrally located bore 38 into which the stub shaft 33 extends. A suitable O-ring seal 40 is provided in an accommodating groove in the bore 38 and seals around the stub shaft 33. An annular bearing 42 is seated in a counterbore 44 formed in the closure plate 34 and journals the stub shaft 33. In like manner, the closure plate 36 has a bore 46 disposed centrally therein, and has a groove 48 formed in this bore to accommodate a seal 50 which seals around the stub shaft 35. A counterbore 52 is formed in the closure plate 36 and receives an annular bearing 54 which rotatably journals the stub shaft 35.

In an annular recess 56 formed in the closure plate 39 around the bore 38 is located a ported seal plate designated generally by reference numeral 58. The seal plate 58 sealingly contacts a wear plate 60 which is seated in a counterbore 62 formed in the closure plate 39. In an annular recess 64 formed around the bore 46 through the closure plate 36, a ported seal plate designated generally by reference numeral 66 is located, and sealingly engages a wear plate 68 which is positioned in a counterbore 70 formed in the closure plate 36. The wear plates 60 and 68 are secured to, and sealingly engage, a pair of hydraulic drive units designated generally by reference numerals 72 and 74 and hereinafter described in greater detail. The hydraulic drive units 72 and 74 constitute drive mechanisms constructed in accordance with the present invention and are each secured by bolts or other suitable securing devices to the end faces 12 and 14, respectively, of the rotor 10. Thus, the hydraulic drive units 72 and 74 and the wear plates 60 and 68 rotate with the rotor 10.

It should be here pointed out that the wear plates 60 and 68 and the seal plates 58 and 66 form no part of the present invention except as they are used in combination with the drive mechanisms of the invention, and these elements of the energy exchange engine depicted in FIG. 1 are described in detail in copending US. application Ser. No. 773,837 assigned to the assignee of the present application. Before proceeding to a detailed description of the hydraulic drive units 72 and 74 which are constructed in accordance with the present invention, however, it will be helpful to the subsequent description to point out that the closure plate 36 has extending therethrough, a pair of fluid passageways or ports, these being a low-pressure fluid inlet passageway or port formed through the closure plate and a high-pressure fluid discharge passageway or port 82 also formed through the closure plate 39 on the opposite side thereof from the low-pressure fluid discharge port 80. In similar fashion, an elongated, highpressure fluid inlet port or passageway 84 extends through the closure plate 39 in a direction substantially parallel to the bore 38 through this closure plate, and a low-pressure fluid discharge passageway or port 86 is formed on the opposite side of the closure plate 39 and extends parallel to the high-pressure inlet port 84. Suitable conduits 88 and 90 deliver low-pressure fluid to the port 80, and receive high-pressure fluid from the port 32, respectively. Similarly, suitable conduits 92 and 94 deliver high-pressure fluid to the port 84 and receive low-pressure fluid from the port 86, respectively.

The highpressure inlet passageway or port 84 in the closure plate 39 communicates with a high-pressure port 95 through the seal plate 56, which high-pressure port is bounded by an arcuate seal plate retainer flange 96. Similarly, the low-pressure discharge passageway or port 86 communicates with a low-pressure port 97 through the seal plate 56, which port is bounded by an arcuate seal plate retainer flange 98. The seal plate retainer flanges 96 and 98 aid in retaining the seal plate 58 in the illustrated position and bound the highand lowpressure ports 95 and 97 through the seal plate. The ports 95 and 97 are of arcuate configuration as illustrated by the dashed lines illustrating similar ports in FIG. 3. The high-pressure discharge passageway or port 82 communicates with the interior of an arcuate seal plate retainer flange 100 shaped substantially identically to the shape of the arcuate seal plate retainer flange 96, and bounding a high-pressure port 101 in the seal plate 66. The low-pressure discharge passageway or port 80 communicates with the zone inside an arcuate seal plate retainer flange 102 which is also shaped like the retainer flanges 96, 98 and 100, and which bounds the arcuate lowpressure port 103 in the seal plate 66. Positioned in alignment with the several axial bores which extend through the rotor are openings formed through the wear plate 60, the two which are visible in FIG. 1 being designated 104 and 106. Similarly, circumferentially spaced openings are formed through the wear plate 68 and are aligned with the bores through the rotor 10.

The construction of the hydraulic drive units 72 and 74 may be best understood by referring to FIG. 2 in conjunction with FIG. 1. It will here be noted that each of the identically constructed hydraulic drive units 72 and 74 includes a disk block 112 which is secured to the respective end face 12 or 14 of the rotor 10 by means of screws or bolts 114, and which is keyed to the respective stub shaft 33 or 35 by means ofa suitable key 116 which is fitted in mating grooves in the respective stub shaft and the disk block 112. Each of the disk blocks 112 of the two hydraulic drive units 72 and 74 is thus secured flatly against the adjacent end face of the rotor 10 and rotates with the rotor. Suitable O-ring seals 118 are provided between the face of the disk block 112 of the hydraulic drive unit 72 and the end face 12 of the rotor 10 around each of the elongated, axially extending bores which extend through the rotor, so that no fluid is permitted to leak between the disk block and the end face of the rotor. In similar fashion, O-ring seals 119 are provided around the openings to each of the elongated, axially extending bores in the rotor at the end face 14 thereof for establishing a seal between this end face and the disk block 112 of the adjacent hydraulic drive unit 74. Seals 120 and 121 are also provided between the wear plates 60 and 68 and the hydraulic drive units 72 and 74.

Each of the disk blocks 112 of the two hydraulic drive units 72 and 74 has a plurality of circumferentially spaced openings or ports 122 formed therethrough in a position spaced radially outwardly from the axis of rotation of the rotor 10, and positioned for registry with the several elongated, axially extending bores which are formed through the rotor. Thus, fluid flowing to and from the axial bores in the rotor 10 enters the respective aligned port 122 formed in the adjacent disk block 112 of the respective hydraulic drive unit 72 or 74. Each of the disk blocks 112 of the two hydraulic drive units is provided with radially extending cylindrical bores 124 which each intersect one of the ports 122 extending through the disk block. There are further provided in each disk block 112, a series of counterbores 126, with each of these counterbores communicating with one of the bores 124.

Reciprocably positioned in each of the cylindrical bores 124 is a piston 128 which has its outer periphery sealingly engaged by suitable sealing elements 131) to prevent fluid bypass of the piston. The radially outer end of each piston 128 bears against a roller block 132 which is reciprocably mounted in the counterbore 126. In the illustrated embodiment of the invention, both the roller block 132 and the counterbore 126 are of sub stantially rectangular crosssectional configuration. Rollably journaled in each roller block 132 is a roller 134. Each of the rollers 134 is, as shown in FIG. 2, in contact with the inner peripheral surface of the eccentric sleeve 34. It will be noted in referring to the cross-sectional configuration of the eccentric sleeve 34 as illustrated in FIG. 2 that the outer peripheral surface of this sleeve which engages the internal surface 320 of the housing 32 is formed concentrically with respect to the rotational axis of the rotor 10 as extended through the stub shaft 35. The internal peripheral surface of the eccentric sleeve 34, however, is formed eccentrically with respect to this axis so that that portion of the sleeve which is located near the left side of FIG. 2 is of lesser thickness than the portion of the sleeve located toward the right side of FIG. 2. Stated differently, the center of curvature of the eccentric inner surface 34a of the eccentric sleeve 34 is displaced laterally from the center of curvature of its external surface, and from the center of curvature of the inner and outer cylindrical surfaces of the housing 32.

The operating principles of the drive mechanism of the invention can best be explained by reference to FIG. 3 of the drawings. Here a disk block forming a part of a drive mechanism similar to the hydraulic drive units 72 and 74 illustrated in FIG. 1 is schematically depicted, and is designated by reference numeral 140. The disk block 140, it will be understood, is secured to and movable with a rotating body (not shown), such as the rotor 10 of the energy exchange engine depicted in FIG. 1. The disk block has one or more openings or ports 142 each formed therethrough in alignment with a bore or fluid passageway formed through the rotating member and alternately receiving relatively high-pressure fluid and relatively low-pressure fluid as the rotating member is rotated. Such bores thus correspond to the axially extending bores (such as 16 and 18) formed in the rotor 10 ofthe energy exchange engine shown in FIG. 1, with these latter bores acting at various times to convey relatively highand relatively low-pressure fluids in a manner hereinafter explained.

The opening 142 in the disk block 140 communicates with a radially extending cylinder 144 which is formed in the disk block, and which slidingly and reciprocably receives a piston 146. The piston 146 has projecting radially outwardly therefrom, a piston rod 148 which bears at its outer end against a cylindrical surface 150 which is disposed eccentri cally with respect to the axis of rotation of the rotating body and of the attached disk block 140. This axis of rotation extends through point 0 which is the center of curvature of the outer peripheral surface of the disk block 140. The center of curvature of the cylindrical surface 150, on the other hand, is designated by reference numeral 0 and is seen to be displaced or offset from the point 0. The cylindrical surface 150 constitutes the inner peripheral surface of an eccentric member 152, such as the eccentric sleeve 34 utilized in the energy exchange engine depicted in FIG. 1. The eccentric member 152 is shown as confined within a cylindrical housing 154 which may be likened to the housing 32 depicted in FIG. 1.

Shown in dashed lines in FIG. 3 are the outlines of a pair of arcuate openings, these being referred to as a high-pressure opening or port 156 and as a low-pressure opening or port 158. These ports are like those formed through the seal plates 58 and 66 and bounded by the arcuate seal plate retaining flanges formed on the closure plates 39 and 36 in FIG. 1, and function to supply a fluid at relatively high pressure (in the case of the port 156) and a fluid at relatively lower pressure (in the case of the opening 158) in alternating sequence to the bores provided through the rotatably mounted body secured to the disk block 140, such fluids being conveyed to and from these bores through openings which are provided in the disk block 140. Thus, it will be noted that the opening 142 is positioned in the disk block 140 for registry in alternating sequence with the high-pressure port 156 and the low-pressure port 158 as the rotor and the disk block 140 carried thereby are rotated about the rotational axis which extends through point 0. It will be understood, of course, that for purposes of explaining the operating principles of the present invention, the schematic drawing of F IG. 3 illustrates only a single opening 142, a single-cylinder bore 144, and a singlepiston element 146, even though a plurality of these elements would be provided in the disk block 140 in operating embodiments of the invention, similar to the number of equivalently functioning elements provided in the embodiment depicted in FIG. 2 of the drawings,

When a bore through the rotor is communicated through one of the openings 142 in the disk block 140 with the high pressure port 156 formed through, for example, a seal plate which is adjacent the disk block 140, the high pressure of the fluid will force the piston 146 outwardly in the cylinder 144 so that the piston rod 148 bears continuously against the cylindrical surface 150. This surface is, of course, eccentric with respect to the axis of rotation of the disk block 140 and any rotatably mounted body attached thereto. The magnitude of the force which is applied through the piston rod 148 to the surface 150 is equal to 2 A where A is the piston area, and p is the pressure of the relatively high-pressure fluid at the highpressure port 156. This pressure, of course, acts in the opening 142 and in the cylinder 144 radially inwardly of the piston 146. Opposing the applied force directed against the surface 150 by the piston rod 148 is a reaction force developed by the eccentric surface. This reaction force acts radially inwardly with respect to the center of curvature O of the eccentric surface. The direction of the outwardly acting force applied to the eccentric cylindrical surface 150 through the piston rod 148 is thus angled with respect to the direction in which the reaction force acts, the angle separating the directions of action of the two forces being designated as The reaction force which acts along a radius, R, of the eccentric surface 150 can be broken into two force components. One of these extends exactly opposite the force applied through the piston rod 148 to the eccentric surface 150, and the other acts perpendicular to the direction of this applied force. The force component acting perpendicular to the applied force generates a torque which causes rotation of the disk block and the rotatably mounted body attached thereto. Thus, the torque, T, generated by the radially moving piston 146 and piston rod 148 in an angular position 0 (measured with respect to a line projected through the points 0 and O) is given by,

p bore pressure and pressure in cylinder 144 (p.s.i,)

A area of piston face exposed to fluid pressure (square inches) 1 =distance between center of rotation, 0, and the point of contact between the piston and the eccentric circle (inches) 6 the angle between the applied force and the reaction force (radians) For the purposes of explanation, it may be considered that the fluid at relatively high pressure P from port 156 acts on the piston 146 for the condition O G 'rr, and that the fluid at relatively low pressure F from port 158 acts on the piston 146 for the condition ne -221i. When 0=(), 6' is also zero, and there is at this time no net torque. As 9 increases, the resultant torque also increases to a maximum, and then declines to zero again when 9==rr(l80). For rr 9s21r, the piston 146 is pushed inwardly against the pressure acting in the opening 142 and within the cylinder 144 at this time.

lf the eccentricity of the surface 150 is properly related to the geometric orientation of the high-pressure and low-pressure ports 156 and 153, respectively (as it is in FIG. 3), the relatively low-pressure fluid (at pressure P,) can be made to act upon the piston 146 at this time. In this region, there is a negative resultant torque (since the perpendicular component of the reaction force acts now in the opposite direction from the direction of rotation), and this negative torque, of course, resists rotation of the rotor. This negative torque is zero at 9 7:- and 6=21r, and it reaches a maximum absolute value as 8 is increased from ntoward 211. The value of the resultant torque at any time is, however, a function of the pressure p acting on the piston 146 as shown by Equation l Therefore, the negative torque which is applied to the disk block during the time that the angle 0 is between 1r and 211' is smaller than that of the positive torque generated as 0 is being increased from zero to 7r at a time when the opening 142 in the disk block 140 is aligned with the high-pressure port 156. in other words, since the pistons 146 are pushed inwardly against relatively low pressure fluid during the time when the eccentricity of the surface 150 results in the generation of a negative torque, the absolute value at the resultant negative torque for a value of 9 between 1rO OZ'ir is smaller than that of the resultant positive torque generated in the region where 0 has a value of between 0 and 1: by a factor of P /P Referring back to Equation (1), and to FIG. 3A, it will be noted that l and 6' are both functions of the angular position, 0, the eccentricity, e, (i.e., the distance 0 0') and the radius, R, of the eccentric surface 150 Thus, the following expressions may be obtained:

T(6) the torque developed when pistons are at the angular position 6, in inch-lbs Assuming that the speed of rotation is s revolution per minute (r.p.m.) and that p (0)=p for (i fl rr p for 1r 9 21r the average power output, becomes E=s'e-A'J l %)sin6'dl9 3 0 R e sin 6 2e A -s(p p inch-lbJminute (4) 26 A 0 2 P1)/ horsepower (5) The average torque, T, is then,

P 211- s T 32 in,-lb./min.

25G01rs/12,672 ,000 horsepower OPERATlON The drive mechanism of the present invention will be seen from the foregoing description to provide a device by which hydraulic or pneumatic pressure can be utilized for developing torque applied to a rotatably mounted body. Thus, the hydraulic drive units 72 and 74 illustrated in conjunction with the energy exchange engine in FlG. 1 are utilized to drive the rotor in rotation, and function to replace a motor which would otherwise necessarily be connected for driving purposes to an extension of one of the stub shafts 33 or 35. Such motor driven operation is described in U.S. Pat. No. 3,431,747.

When the hydraulic drive units 72 and 74 are employed for driving the rotor 10 of the energy exchange engine in rotation, the manner in which the structure depicted in FIGS. 1 and 2 functions is as follows. Let it be assumed at the outset that two process liquids which shall be called liquid A and liquid B are available in an industrial process at pressures P and P respectively. Let it be assumed that the pressure P ofliquid B is substantially greater than the pressure P of liquid A. it is not material what two liquids are employed and, in fact, both of the liquids may be a slurry. Gases may also be employed, although the preferred and most advantageous use of the pressure exchange engine occurs when liquids or pumpable slurries are utilized.

With a source of liquid A at pressure P available, this source is connected to the low-pressure fluid inlet passageway 80 through the conduit 88 so that liquid A at pressure P may enter this passageway, and from this passageway be passed through the low-pressure arcuate port through the seal plate 66 and defined by the arcuate seal plate retainer flange 102. From the low-pressure arcuate port in the seal plate 64, the liquid A at pressure P passes through openings such as the opening 110 in the wear plate 68 and cnters one or more of the openings 122 formed through the disk block 112 of the hydraulic drive unit 74, as such openings through the disk block may at that time be in registry with the low pressure arcuate port in the seal plate 66 through the aligned or registering openings 122 in the wear plate 68. Thus, the liquid A at the relatively low pressure P comes to act upon the inner face of the pistons 128 which project into the openings or ports 122 then aligned to receive such relatively low-pressure liquid. The low-pressure liquid also passes into the axial bores, such as bore 18, through the rotor 10 which are aligned with the ports 122 through the disk block 122, which in turn are aligned with the low-pressure arcuate port through the seal plate 66. Relatively low-pressure fluid is concurrently acting outwardly on the pistons 128 so as to force the rollers 134 outwardly against the inner peripheral surface of the eccentric sleeve 34. From the previous discussion herein, it will be understood that the portion of the inner surface 340 of the eccentric sleeve 34 against which the rollers 134 at this time bear is that portion over which the distance separating this surface from the external peripheral surface of the rotor 10 is decreasing (or, stated differently, the portion of the inner peripheral surface 34a of the eccentric sleeve 34 over which the angle 6 is increasing from 11 to 211' as previously described). Thus, the inward motion of pistons 128 against the force of the low pressure fluid generates negative torque. The passageway 86 through the closure plate 39 is connected to a relatively low-pressure zone, in most instances, at atmospheric pressure. Thus, the balls 28 will be reciprocated in the axial bore 18 and similarly located rotor bores toward the left as viewed in FIG. 1 under the impress of the relatively low-pressure fluid entering this bore from the passageway 80 in the closure plate 36 via the seal plate 66, the wear plate 68 and certain of the ports 122 formed in the disk block 112 of the hydraulic drive unit 74.

The high-pressure inlet passageway 84 in the closure plate 39 receives the liquid B from the conduit 92, this liquid being at the relatively high pressure P,. Finally, the high-pressure discharge passageway 82 is connected to suitable liquid confining means which can retain a liquid under pressure, and can permit the liquid under pressure to be pumped thereinto from the high-pressure fluid discharge passageway 82 via the conduit 90.

After the relatively high-pressure liquid B passes from the passageway 84 through the arcuate high-pressure port pro vided in the seal plate 58, and through the series of registering ports 104 provided through the wear plate 60, this high-pressure liquid then enters the particular group of the ports 122 through the disk block 112 of the hydraulic drive unit 72 which are also in alignment or in registry with the arcuate high-pressure port in the seal plate 58. The group of radial cylinders 124 formed in the disk block 112 of the unit 72 which communicate with the ports 122 receiving high-pressure liquid B at this time are thus also filled with this high-pressure liquid, and the pistons 128 reciprocably mounted in these respective cylinders are forced radially outwardly by the highpressure liquid. The rollers 134 are thus caused to develop a force acting on the eccentric cylindrical surface 34a of the eccentric sleeve 34, and by proper arrangement of the sleeve, as hereinbefore described, a net positive torque is developed tending to cause the rotor 10 to undergo rotation. This net positive torque is, of course, of greater magnitude than the negative torque developed as a result of the action of pistons 128 against the relatively low pressure liquid A on certain others of the pistons 128 due to the higher magnitude P of the pressure at which the liquid B is introduced to the hydraulic drive unit from the passageway 84.

After passing through the ports 122 in the disk block 112 of the hydraulic drive unit 72, the high-pressure liquid B enters the axial bores in the rotor 10 which at that time communicate through the ports 122 with the high-pressure arcuate port in the seal plate 58. The ball 28 is thus forced to the right in these bores so as to displace liquid located in the axial bore to the right of this ball, and force this liquid into the confining means previously described so as to build up the pressure of the liquid contained in such confining means. Due to the confinement of the liquid discharged from the high-pressure discharge passageway 82 and the conduit connected thereto, the liquid contained in the axial bores 16 of the rotor 10 on the right side of the ball 28 is also at relatively high pressure in comparison to the relatively low-pressure liquid A which is passing into the axial bores 18, and also in comparison to the liquid being discharged from these latter bores. Thus, a relatively high pressure acts redially outwardly against the inner ends of the pistons 128 which are carried in cylinders 124 at that time in communication with certain ports 122 which are in registry through the ports 108 in the wear plate 68 with the arcuate high-pressure port through the seal plate 66. These particular pistons 128 are thus forced radially outwardly with respect to the rotor 10 by the relatively high-pressure liquid acting thereon, and due to the arrangement of the eccentric sleeve 34 in relation to the high-pressure arcuate port of the seal plate 66, a relatively high magnitude positive torque is developed by the contact of the rollers 134, positioned radially outwardly of these pistons, with the inner peripheral surface of the eccentric sleeve.

From what has been described relative to the manner in which the high-pressure liquid B and the low-pressure liquid A pass through the closure plates 39 and 36, the seal plates 58 and 66, and the two hydraulic drive units 72 and 74, it will be perceived that at all times, a net positive torque will be developed which will cause the rotor 10 to be rotated about its axis. The energy exchange engine is thus actuated through the utilization therewith of the drive mechanism of the present invention. The structure thus provided can be utilized for efficiently transferring substantially all of the pressure energy from the relatively high-pressure liquid B to the relatively lowpressure liquid A. Having set the rotor 10 in rotational motion due to the reaction forces developed and acting through the pistons 128 of the hydraulic drive units 72 and 74, the axial bores, ofwhich the bores 16 and 18 depicted in FIG. 1 are typical, are, in consecutive sequence, brought into axial alignment through the registering ports in the disk blocks of the two hydraulic drive units with the arcuate high-pressure and low-pressure ports formed in the seal plates 58 and 66, and diagrammatically illustrated in FIG. 3 of the drawings. With the alignment of the axially extending bores 16 and 18 depicted in FIG. 1, which may be considered as a typical alignment which will occur with respect to the other axially extend ing bores formed through the rotor 10, the relatively low-pressure liquid A at pressure P enters the bores aligned as is bore 18 to the right of the ball 28 via the low-pressure fluid inlet passageway 80, and the ports through the wear plate, and the ports through the hydraulic drive unit 74. At the same time, some of liquid B which has been previously entrapped in the part of the bore 18 to the left ofthe ball 28 in these same bores is placed in communication with a vent or low-pressure environment, and can be discharged through the low-pressure fluid discharge passageway 86 and the conduit 94 as the balls 28 are displaced to the left in these bores by the impress of the relatively low-pressure liquid A entering the right sides of these bores.

in the case of bores located similarly to the axially extending bore 16 at the instant depicted in FIG. 1, the relatively highpressure liquid B at pressure P which enters the left side of these bores from the high-pressure fluid inlet passageway 84 drives the balls 28 toward the right. This displaces the entrapped liquid A which is disposed in the right side of these bores as a result of its entry into these bores at a previous time when the bores occupied positions similar to that shown as occupied by the bore 18 in FIG. 1. This occurred, of course, at a time earlier in the rotational movement of the rotor 10. Continued impress of the high-pressure liquid B upon the left side of the balls 28 eventually drives the balls to the right side of these bores and completely displaces the relatively low-pressure liquid A from these bores at a pressure which is here only slightly less than that of the high-pressure liquid B as a result of the confinement of the fluid A being discharged via the conduit 90.

it may thus be seen that as the rotor continues to rotate, the net effect is that, in being depressurized from its elevated pressure P to atmospheric pressure, the high-pressure liquid 8 is made to transfer effectively its energy of pressurization to the relatively lower-pressure liquid A. The transfer is highly efficient due to the minimum energy requirement to displace the balls 28 in their respective bores, and no valving is included in the system which can become choked or clogged by any entrained material carried in the liquids between which the energy transfer is to take place. Thus, relatively thick slurries of high solids content can be successfully passed through the pressure exchange engine without damage to it, despite its use over extended periods of time for transferring pressure energy between such slurries.

A relatively small amount of the pressure energy of the high-pressure liquid is dissipated in forcing the pistons 128 of the hydraulic drive units 72 and 74 outwardly so that the rollers 134 contact the inner peripheral surface of the eccentric sleeve 34 and drive the rotor in rotation. Moreover, it will be perceived that there are no exposed moving parts and no gear reduction devices required when the drive mechanism of the present invention is used for driving the energy exchange engine. As will be subsequently shown, by adjusting the position of the eccentric sleeve 34, a wide range of torque or power output can be obtained with the system which is illustrated. No external source of power is required to provide a driving force for the rotor 10. The work of expansion of the high-pressure liquid in the bores is sufficient to generate the required torque for driving the rotor so that the power used by the hydraulic drive units 72 and 74 can come from the recovering of losses due to sudden depressurization of the high-pressure liquid. This will also be explained in greater detail hereinafter.

TORQUE AND SPEED VARIATION The arrangement depicted in FIG. 3 in one in which the line 00' (interconnecting the center of curvature of the cylindrical surface 150, and the center of curvature of the rotor and disk block 140) exactly divides the zones of high-pressure fluid action and lowpressure fluid action as such fluid pressures are brought to bear upon the piston 146 over periods each roughly approximating one-half the period required for one revolution of the rotor. The manner in which the average net torque developed by the drive mechanism, as well as the speed of the rotor, can be selectively varied will now be discussed, aided by reference to H6. 4. in this schematic illustration, the eccentric surface is designated by reference numeral 160, and the outer peripheral surface of the rotor and, more importantly, of a disk block attached thereto, is designated by reference numeral 162. The center of curvature of the eccentric circle surface is designated again by reference numeral 0', and the center of rotation of the cylindrical outer periphery of the rotor and the disk block is designated by reference character 0. The line CC is the boundary line demarcating that portion of the rotational cycle of the rotor and disk block during which relatively high-pressure fluid acts on the radially reciprocable pistons hereinbefore described, from that portion of the rotational cycle of the rotor over which relatively low pressure fluid acts on these pistons. It will thus be seen that, in this instance, instead of the axis 00 coinciding with the boundary line dividing the high-pressure and low-pressure zones from each other, the 00' axis extends at some angle 6" with respect to the boundary C -C between the highand lowpressure zones. With this arrangement, the average net torque output per piston is given by T=2 eA(P P,) cos 0" 7 where, as has been indicated, 0" is the angle of rotation of the axis 0-0 relative to the boundary line CC separating the high-pressure and low-pressure regions.

For a given drive system, the areas A of pistons upon which the pressurized fluids will act will generally be fixed (constant), and the pressure differential (P P between the highpressure fluid and the low-pressure fluid should be maintained at such value as may be required by the operating conditions. With regard to the latter statement, it will be understood that in such applications as the employment of the present drive mechanism in the energy exchange engine used in the desalination of sea water as described in U.S. Pat. No. 3,431,747, certain pressure differentials between the highpressure and low-pressure fluid will generally prevail so that it may be assumed that for a given system, the pressure differential P2P1 will be a relatively constant condition, or at least will be a parameter not susceptible to control for purposes of varying the torque and speed of the rotated body as hereinafter described.

With the piston areas fixed, as well as the pressure differential, the average net torque output will, as indicated by Equation (7), be variable by either adjusting the angle 6" by rotating the axis 04) (that is, by shifting an eccentric sleeve or other eccentric surface in relation to the rotated body), or by shifting the position of the eccentric cylindrical surface 160 so as to vary the distance, e, which separates the points flfand o'. It will be apparent, for example, that the distance, e, can be reduced to zero so as to result in no net torque-that is, the eccentricity of the surface 160 then no longer exists. Similarly, if 0" is increased to n12, the net torque will become zero. Both of the variables 0" and e can be readily and easily varied to attain any desired torque level or speed.

Thus, the amount of torque derived from the high-pressure fluid acting in the system can be varied either by changing e or by changing 0". In other words, the drive mechanism of the invention can be made to have a maximum design torque output which is several times higher than is required by the rotor or other rotatably mounted body which is to be driven in rotation by the drive mechanism, but the power consumption will always be exactly equal to the power which is required. Such overdesigning can be done at no appreciable additional cost.

Applying the foregoing considerations relative to selected variation of speed and torque control to the system which is depicted in FIGS. 1 and 2, it will be perceived that selective control of these parameters can be easily obtained by providing for any suitable means for rotating the position of the eccentric sleeve 34 within the housing 32. For example, a simple gear drive might be provided to the eccentric sleeve 34 and controllable from outside the housing 32 to cause the eccentric sleeve to be rotated to a selected position within the housing so as to vary the value of the angle and thus adjust the net torque developed and the speed of the rotor as may be desired.

Another embodiment of the present invention is depicted in FIG. 5 of the drawings Here a disk block 164 is provided and is adapted for securement to a rotatably mounted body so as to concurrently rotate about a rotational axis extending through point 0. The disk block has a series of circumferentially spaced ports 166 formed therethrough with the ports being radially spaced outwardly from the axis of rotation by equal distances. The ports 166 are aligned with fluid passageways extending into the rotor or other rotatable body (not shown) to which the disk block is attached for receiving relatively high-pressure fluid and relatively low-pressure fluid therefrom during rotation of the body. Each port 166 communicates with a cylindrical bore 168 which extends inwardly from the outer peripheral surface 170 of the disk block. Each cylindrical bore 168 intersects a counterbore 172 formed in the outer peripheral surfaces of the disk block, such counterbore being threaded to receive a piston stop cap 174.

Disposed within each cylindrical bore 168 is a piston 176 which has an O-ring seal 178 secured therearound for sealingly engaging the wall of the cylindrical bore. Each of the pistons 176 has a semispherical recess 180 formed in the radi ally outer surface thereof to receive a ball 182 secured to one end of a tie rod 184. Each tie rod 184 projects through an opening 136 formed in the respective piston stop cap 174, and the opening 186 is sufficiently large that each tie rod can swivel or pivot about its respective ball 182. At its outer end, each of the tie rods 184 carries a second ball 183 which is pinned by a pivot pin 190 to an eccentric ring or sleeve 192 which eccentrically surrounds the disk block 164', and is eccentric with respect to the axis of rotation of both the disk block and the rotatable body to which it is secured. Thus, the center of curvature upon which the inner peripheral surface 194 of the eccentric ring 192 is formed is indicated by reference character 0' in FIG. 5. The radius of the circle upon which the several points of connection of the tie rods 184 to the eccentric ring 102 are located is designated by reference character R in FIG. 5, and the radial distance between the center of the disk block 164 (rotational axis of the disk block and rotating body), and the contact points between a piston 176 and its respective tie rod 184 is designated by reference character r. The length of the tie rods is indicated by reference character :1.

Surrounding the eccentric ring 192 is a cylindrical or annular bearing member 198. The annular bearing member 198 is concentrically located with respect to the eccentric ring 192, and a suitable bearing race 200 is provided between the annular bearing member and the eccentric ring so that the eccentric ring may rotate within the bearing member. Finally, a cylindrical housing 202 of the type hereinbefore described is provided outside of the annular bearing member 198.

In the operation of the embodiment of the invention partially depicted in FIG. 5, the force exerted on the eccentric ring 192 by the pistons 176 through the tie rods 134 causes the eccentric ring to rotate within the annular bearing member 198, and in undergoing such rotation, to pull the disk block 164 and the rotor secured thereto along with it. When each piston 176 has traveled the full length of its respective cylinder, it is stopped by the respective piston stop cap 174 partially closing the opening to that cylinder, and its respective tie rod 184 is then pulled out by the action of the other pistons which still have room left for outward movement. It is this pulling action against the piston stop caps 174 by the tie rods 184 which creates the necessary torque for turning the disk block 164 and an associated rotatable body, such as the rotor of an energy exchange engine.

One advantage of the use of the drive mechanism of the present invention in a device of the type such as the energy exchange engine is that the drive mechanism requires the diversion of a relatively small amount of the pressurized fluid in comparison to the total fluid throughput through the engine. For example, using hydraulic drive units in conjunction with a typical energy exchange engine, the bores in such an engine will typically be one-half inch in diameter by 24 inches in length (in a pilot or laboratory size device). The amount by which fluid is displaced by these bores into a pair of radial cylinders forming a part of two hydraulic drive units, and communicating with each bore at each end thereof is about onefourth inch each. Therefore, the percent of pressurized liquid which is, in a sense, diverted from the uninterrupted throughput (which would otherwise occur in the exchange engine) for the purpose of operating the hydraulic drive units becomes l00 2/24 which is approximately I percent. As the exchange engine is scaled up to a larger size, this percentage becomes substantially smaller. The amount of expansion of water when its pressure is reduced from 2,500 p.s.i.a. to 30 p.s.i.a. is about 0.8 percent. Therefore, the hydraulic drive units can derive a substantial part of their energy requirements from the available work of expansion of the relatively highpressure liquid.

Yet another embodiment of the present invention is diagrammatically illustrated in FIG. 6 of the drawings. In this arrangement, a fixed semieccentric sleeve 204 is placed radially outwardly of a disk block 206 which is secured to, and rotatable with, a rotor or other rotatably mounted body, about an axis of rotation passing through the point 0. The direction of rotation of the disk block 206 and rotor is indicated by the curved arrow extended around the point 0. Close observation of the semieccentric sleeve 204 will reveal that one-half of the inner surface 208 of the sleeve 204 is formed about the same center of curvature 0 as is the outer peripheral surface 210 of the disk block 206. The other half of the inner peripheral surface 208 of the semieccentric sleeve 204 is, however, eccentrically disposed with respect to the axis of rotation of the disk block 206 and its associated rotor, and therefore has its center of curvature displaced from the point 0. When this structural arrangement is employed, it is utilized in a particular relationship to the fluid ports and passageways through the rotor or other rotating body, which ports and passageways feed highand low-pressure fluid to the cylinders (not shown) disposed around the outer periphery of the disk block 206 in the manner hereinbefore described. Thus, this arrangement may be described as being such that during about one-fourth of one rotational cycle of the rotor and disk block 206, high-pressure fluid is acting upon the pistons carried in the cylinders at the outer periphery of the disk block 206, and this portion of the rotational cycle may be referred to as the high-pressure zone. Another quarter cycle of the rotor and disk block 206 transpires at a time when relatively low-pressure fluid has been passed through passageways or bores in the rotor and into the cylinders located at the outer periphery of the disk block, and this fraction of the rotational cycle may be referred to as a low-pressure zone. These zones are schematically illustrated in FIG. 6.

From what has been previously said in describing the operation of the energy exchange engine depicted in FIG. 1, and from the dashed line illustration of the high-pressure and lowpressure ports, 156 and 158, respectively, in the seal plates as schematically illustrated in FIG. 3, it will be appreciated that between the time that relatively high-pressure fluid if introduced to, and discharged from, one of the axially extending bores or passageways through the rotor of an energy exchange engine, and the time that relatively low-pressure fluid is introduced to and discharged from the same axially extending bore in the energy exchange engine, a period of transition may be said to occur during which this bore in the rotor is isolated from communication with either the source of high-pressure fluid or the source of low-pressure fluid (such as the high-pressure and low-pressure ports 156 and 158 formed in the seal plate may be considered to be). These zones of transition from high to low pressure may be though of as corresponding to the island zones lying between the high-pressure and low-pressure ports 156 and 158 depicted in FIG. 3, these being denominated by reference numerals 212 and 214 in that figure. In other words, as each axial bore of the rotor or other rotatable body attached to a disk block of a drive mechanism of this invention passes across an island area between the ports used to alternately introduce highand low-pressure fluid to this bore, it may be thought of as passing through a transition zone between a high-pressure zone and a low-pressure zone.

FOr purposes of illustration, in the schematic illustration of FIG. 6, these zones of transition have been depicted as occurring during one quarter of a complete revolution of the rotor and disk block 206, and the two zones of transition are schematically illustrated. For this portion (one-fourth) of a complete cycle of the rotor and disk block 206 to be utilized in traversing the two zones of transition, it would actually be necessary to make the ports through which highand lowpressure fluids are introduced to the rotor and drive mechanism (such as the ports 156 and 158 shown in FIG. 3) of a size to communicate with each rotor bore during only onefourth of one period of revolution of the rotor.

It will be noted in referring to FIG. 6 that during the period of time that cylinders and their respective pistons disposed at the outer periphery of the disk block 206 are located opposite the noneccentric portion of the inner peripheral surface 203 of the semieccentric sleeve 204, no torque can be developed by reaction forces generated by contact of piston rods with such surface since no eccentricity is encountered during this period. The absence of eccentricity in the inner peripheral surface 208 of the sleeve 204 is purposely made to be encountered by the pistons carried in the peripheral cylinders of the disk block 206 at a time such that the respective cylinders are either receiving high-pressure fluid from a communicating high-pressure fluid port in a seal plate or the like, and thus are in transit of the high-pressure zone, or, alternatively, are isolated from both highand low-pressure fluid sources, and are in the process of moving from registry with a relatively lowpressure fluid port toward registry with a relatively high-pres sure fluid port.

At such time as the peripheral cylinders on the disk block 206 and the pistons reciprocably located therein are opposite the zone of transition from highto low pressure, the eccentricity of the inner peripheral surface 208 of the semieccentric sleeve 204 is such that the pistons can move outwardly, and reaction forces are developed which tend to drive the disk block 206 in rotation in the direction indicated by the arrow surrounding the point 0. At this time, the cylinders at the outer periphery of the disk block 206 contain a relatively high-pressure fluid, and both they and their communicating fluid passageways in the rotatable body attached to the disk block 206 are isolated from the sources of the relatively high-pressure fluid and the relatively low-pressure fluid. The rotatable body is, however, approaching a position during its rotational cycle such that the bores communicating with these cylinders will next become aligned with the low-pressure port, and lowpressure fluid will be introduced into the bores to drive out or exhaust the high-pressure fluid to the atmosphere as has been explained in referring to the operation of the energy exchange engine shown in FIG. 1.

The described arrangement (in which the positive torque is developed for driving the disk block 206 and associated rotatable body in rotation at a time when the fluid passageways or bores in the rotatable body are in the described transition zone between highand low-pressure fluid) offers the advantage that some of the work of expansion of the relatively high-pressure fluid which would otherwise be lost (as this fluid is exhausted to atmospheric pressure by displacement by the entering relatively low-pressure fluid at such time as communication is established with the low-pressure fluid ports) is, in fact, recovered by using a portion of such work of expansion to drive the pistons in the peripheral cylinders outwardly against the diverging eccentric portion of the inner peripheral surface 208 of the semieccentric sleeve 204. Moreover, by using a part of this work of expansion for this purpose at this time, a gradual depressurization of the relatively high-pressure fluidat this time isolated in the bores or passageways of the rotor or other rotatable body-is effected prior to the time that these bores or passageways are placed in communication with the low-pressure port through the seal plate, and thus a smoother operation of the energy exchange engine or other device in which rotational movement is developed by the drive mechanism of the invention is effected. Also, as will be seen momentarily, this gradual depressurization during the transiting of the transition zone reduces the amount of negative torque which will be developed during transit of the low-pressure zone, since the efi'ect of such depressurization at this stage is to lower the pressure acting in the peripheral cylinders of the disk block 206 during the time that the eccentricity of the semieccentric sleeve is such that negative torque is developed.

The peripheral cylinders and the pistons therein are rotated opposite the converging eccentric portion of the inner peripheral surface 208 of the semieccentric sleeve 204 at a time when the bores or passageways communicating with these cylinders are receiving relatively low-pressure fluid. Thus, as has been described in referring to the energy exchange engine shown in FIG. 1, the axially extending bores through the rotor 10 will, at this time, be communicated with the relatively low-pressure ports in the seal plates at opposite ends of the rotor, so that the relatively high-pressure fluid which has previously been entrapped in the bore will at that time be discharged to atmospheric pressure under the impress of relatively low-pressure fluid moving into the bore from the registering low-pressure fluid port in the aligned seal plate. It is during the occurrence of this type of fluid flow through certain bores in the rotor and into communicating peripheral cylinders on the disk block 206 that these cylinders and the pistons which they carry may be said to be transiting the lowpressure zone. As has been previously described, the converging eccentricity of the surface 208 at this time develops a reaction force producing negative torque which tends to oppose rotation of the disk block 206 and the rotor associated therewith in the desired direction of rotation as indicated by the arrow. However, due to the relatively low pressure applied to the cylinders at this time, this negative torque is small in comparison to the positive torque developed during the passage of the peripheral cylinders and their pistons through the transition zone from high to low pressure as previously described. Moreover, the pressure acting on the pistons has been even further reduced than would normally be the case with a drive system of the type depicted in FIGS. 1, 2 and 4, in that some of the pressure energy has been expended during the passage of the zone of transition from high to low pressure for the purpose of forcing the pistons outwardly at that time.

When the work of fluid expansion is more than is required to operate the drive mechanism of the invention, the semieccentric sleeve 204 can be further modified with respect to the configuration of the inner peripheral surface 210 so as to allow partial inward movement of the pistons as they pass through the zone of transition from low pressure to high pressure. This arrangementallows partial compression of the fluid in the bores due to inward movement of the pistons in the peripheral cylinders prior to the time that the bores in the rotating body are placed in communication with the high-pressure ports through the seal plates at opposite ends of the body. Alternatively, one can use the hydraulic drive unit to precompress the low-pressure liquid to the full pressure prior to communication with this high-pressure port if the eccentricity and stroke of the pistons and piston rods moved thereby are sufficiently dimensioned. With an arrangement of this type, the movements of the pistons when the bores of the rotor or other rotatable body are in communication with a high-pressure source will provide the necessary energy which may be required to rotate the rotorv The expansion work is utilized to precompress the low-pressure fluid.

Although certain preferred embodiments have been herein described in order to provide examples of the manner in which the drive mechanism of the present invention may be constructed and, more importantly, of the operating principles which underlie such drive mechanism, it is to be understood that a number of changes in the arrangement of structural ele mcnts, and in their relationship to each other, can be made without departure from the basic principles of the invention. Changes and innovations of this type are therefore deemed to be circumscribed by the appended claims or reasonable equivalents thereof.

What is claimed is:

1. A drive mechanism comprising:

a cylindrical rotor having planar end faces and a rotational axis extending centrally through said rotor between said end faces, said rotor having fluid conveying axial bores extending therethrough between the end faces and radially offset from the axis rotation;

a movable piston element reciprocably mounted in each bore;

stationary structures positioned opposite each end face of the rotor, and each having at least two spaced fluid ports therein positioned for sequential periodic registry with each of the bores through the rotor during the rotation of the rotor for alternately introducing to each of said axial bores from the spaced fluid ports in each of said stationary structures, first a relatively high-pressure fluid and then a relatively low-pressure fluid, the fluid ports in one of said stationary structures being aligned with the fluid ports in the other of said stationary structure so that two fluid ports at opposite ends of the rotor communicate concurrently with each other through one of said axial bores each time one of said axial bores registers with any one of the fluid ports, whereby said relatively high-pressure fluid may be introduced to each of said axial bores on one side of said movable piston therein concurrently with the expulsion of relatively low pressure fluid from the same respective axial bore at a location on the opposite side of said movable piston with said introduction and expulsion taking place through two of said ports concurrently aligned with said respective axial bore;

cylinders connected to said rotor for rotation therewith, and including a pair of cylinders communicating with each of said bores at locations on opposite sides of the movable piston element reciprocably mounted in the respective bore, said cylinders thus being positioned for receiving fluid under pressure from the portions of each bore on opposite sides of the respective movable piston element therein, all of said cylinders being disposed radially outwardly relative to the axis of rotation of said rotor;

piston means reciprocably mounted in each of said cylinders for reciprocating movement in a direction extending radially from the axis of rotation of said rotor; and

a continuous surface around said axis of rotation externally of said cylindrical rotor, and having a portion which is eccentric with respect to said axis of rotation, said continuous surface being positioned radially outwardly from said cylinders and piston means, said piston means contacting said continuous surface continuously during rotation of said rotor and said cylinders connected thereto for rotation therewith.

2. A drive mechanism as defined in claim 1 wherein the ports in said stationary structures are arranged relatively to the eccentricity of said continuous surface, and the location of said cylinders and piston means located therein is, such that high-pressure fluid may be introduced through at least one of said ports to each of said axial bores at a time when the piston means in the respective cylinder communicating with the respective bore sustains a reaction force in contacting said eccentric surface which causes the rotor to rotate in one direction, and such that relatively lower-pressure fluid may be introduced through at least one of said ports in the stationary structure at the opposite end of said rotor to each of said axial bores at a time when the piston means in the respective cylinder at that time communicating with that respective axial bore sustains a reaction force in contacting said eccentric portion of said continuous surface which opposes rotation of the rotor in said one direction, whereby the net torque imparted to said cylindrical rotor via said cylinders connected thereto as a result of the reaction forces described is a torque driving said rotor in rotation in said one direction.

3. A drive mechanism as defined in claim 1 wherein said continuous surface has a semicylindrical portion which is concentrically disposed relative to the axis of rotation of said rotor mounted body.

4. A drive mechanism as defined in claim 1 wherein said continuous surface is rotatable about the axis of rotation of said cylindrical rotor whereby the distance separating any one of said cylinders at a particular time during the rotation of said continuous surface, from a point in said cylindrical surface, can be selectively varied to vary the torque developed by said drive mechanism.

5. A drive mechanism as defined in claim 1 wherein said continuous surface includes a pair of interconnected semicylindrical portions, one of said semicylindrical portions being concentric to said axis of rotation of the cylindrical rotor, and the other semicylindrical portion being eccentric with respect to said axis of rotation of the cylindrical rotor.

was UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Dated February 15, 1972 Patent No. 3 881 Inventor(s) Hadl Hasheml It is certified that error appears in the above-identified patent and that said Letters Patent are hereby corrected as shown below:

Column 8, line 19, 7T 0 0'2 77" should be 77 and 2 77'--.

Column 8, line 28, the function within the radical should )6 Stead \m Coiumn 8., line 53, "p in.-lb.p should be'-- p p Column 12, line 28, insert -thebefore the word "pistons."

Column 12, line 51, "0g afid 0'" should be --0 and Signed and sealed this fith day of July 1972.

(SEAL) Attest:

EDWARD PLFLHICHER, JR. ROBERT GOTTSCHALK Attesting Officer Commissioner of Patents 

1. A drive mechanism comprising: a cylindrical rotor having planar end faces and a rotational axis extending centrally through said rotor between said end faces, said rotor having fluid conveying axial bores extending therethrough between the end faces and radially offset from the axis rotation; a movable piston element reciprocably mounted in each bore; stationary structures positioned opposite each end face of the rotor, and each having at least two spaced fluid ports therein positioned for sequential periodic registry with each of the bores through the rotor during the rotation of the rotor for alternately introducing to each of said axial bores from the spaced fluid ports in each of said stationary structures, first a relatively high-pressure fluid and then a relatively lowpressure fluid, the fluid ports in one of said stationary structures being aligned with the fluid ports in the other of said stationary structure so that two fluid ports at opposite ends of the rotor communicate concurrently with each other through one of said axial bores each time one of said axial bores registers with any one of the fluid ports, whereby said relatively high-pressure fluid may be introduced to each of said axial bores on one side of said movable piston therein concurrently with the expulsion of relatively low-pressure fluid from the same respective axial bore at a location on the opposite side of said movable piston with said introduction and expulsion taking place through two of said ports concurrently aligned with said respective axial bore; cylinders connected to said rotor for rotation therewith, and including a pair of cylinders communicating with each of said bores at locations on opposite sides of the movable piston element reciprocably mounted in the respective bore, said cylinders thus being positioned for receiving fluid under pressure from the portions of each bore on opposite sides of the respective movable piston element therein, all of said cylinders being disposed radially outwardly relative to the axis of rotation of said rotor; piston means reciprocably mounted in each of said cylinders for reciprocating movement in a direction extending radially from the axis of rotation of said rotor; and a continuous surface around said axis of rotation externally of said cylindrical rotor, and having a portion which is eccentric with respect to said axis of rotation, said continuous surface being positioned radially outwardly from said cylinders and piston means, said piston means contacting said continuous surface continuously during rotation of said rotor and said cylinders connected thereto for rotation therewith.
 2. A drive mechanism as defined in claim 1 wherein the ports in said stationary structures are arranged relatively to the eccentricity of said continuous surface, and the location of said cylinders and piston means located therein is, such that high-pressure fluid may be introduced through at least one of said ports to each of said axial bores at a time when the piston means in the respective cylinder communicating with the respective bore sustains a reaction force in contacting said eccentric surface which causes the rotor to rotate in one direction, and such that relatively lower-pressure fluid may be introduced through at least one of said ports in the stationary structure at the opposite end of said rotor to each of said axial bores at a time when the piston means in the respective cylinder at that time communicating with that respective axial bore sustains a reaction force in contacting said eccentric portion of said continuous surface which opposes rotation of the rotor in said one direction, whereby the net torque imparted to said cylindrical rotor via said cylinders connected thereto as a result of the reaction forces described is a torque driving said rotor in rotation in said one direction.
 3. A drive mechanism as defined in claim 1 wherein said continuous surface has a semicylindrical portion which is concentrically disposed relative to the axis of rotation of said rotor mounted body.
 4. A drive mechanism as defined in claim 1 wherein said continuous surface is rotatable about the axis of rotation of said cylindrical rotor whereby the distance separating any one of said cylinders at a particular time during the rotation of said continuous surface, from a point in said cylindrical surface, can be selectively varied to vary the torque developed by said drive mechanism.
 5. A drive mechanism as defined in claim 1 wherein said continuous surface includes a pair of interconnected semicylindrical portions, one of said semicylindrical portions being concentric to said axis of rotation of the cylindrical rotor, and the other semicylindrical portion being eccentric with respect to said axis of rotation of the cylindrical rotor. 